Put yourself in Herod's shoes. What is your response to the Wise Men's news?
This translation says he was "troubled." The Greek word is "tar-as-so." Herod was tar-as-soed. I repeated it three times and finally it came out properly with the English equivalent: "tar-as-soed...TERRIFIED!"
Why would Herod be terrified of a Baby? Doesn't it seem irrational and over the top?

Herod sensed this Baby, or rather what this Baby would become, was a threat.
Indeed, the Baby was. In fact, this Baby would grow up and threaten everyone and every institution that attempts to control others through fear. This Baby would remove our reasons to fear...and that terrified Herod.
How does this Baby enable you to live fearlessly?
How is this "good news of great joy" in your current context?

“When Herod the king had heard these things, he was troubled, and all Jerusalem with him”
The New Testament often uses general terms (ALL) to distinguish specific groups of people, For example, "all" is used to mean those of the Pharisees, Sadducees, Scribes, and of course Herod (his wife was Jewish and he was an Edomite), as opposed to Simeon/Anna and the excited populace. Remember how Herod also tried to curry favor with Jewish leadership by building them a Temple, yet at the same time ruling with FEAR over his subjects to stay in absolute control (even over family relatives via murder).
Terrified with sleepless nights thinking that even during his lifetime (albeit even as an old man), or later after his death, his legacy would be forgotten in Jewish history if replaced by a newly coming King, which must have caused him to be greatly distressed by the thought of being forgotten.
Christians today as in the past, along with future Christians, will find it hard to understand this FEAR expressed by Herod in our scripture reading. We enjoy the peace and comfort daily that Christ The King has provided for us by “HIS” Grace and Mercy daily until that time of our everlasting PEACE in HEAVEN (Church Triumphant).
Happy New Years, my brothers and sisters in Christ
Harry O.

Without Christ I can think of plenty of things to be fearful of in this world but with Christ there's a peace and a hope that comes from knowing that He has already overcome the world, John 16:33, and that nothing can ever separate us from His incredible love, Romans 8:38-39.